The present invention relates to a capacitor and, more particularly, to an arrangement of a capacitor made of ceramics.
Generally, capacitors of the foregoing type include a ceramic body having two electrodes deposited thereon and two terminal pins extending from the respective electrodes. The manner in which the terminal pins are provided effects the retention of such pins during and after the manufacture of the capacitor.
One conventional capacitor arrangement includes a cylindrical ceramic body 1, as shown in FIGS. 1a and 1b, which has been sintered. Each end of the ceramic body 1 is grinded to form a concave surface on which an electrode film 2 or 3 is deposited. Two terminal pins 4, each having a head portion 4a (FIG. 2) are attached axially to the cylindrical ceramic body 1 at opposite ends thereof with the head portion 4a being held in contact with the concave electrodes 2 and 3, respectively, as shown in FIG. 3. To secure the terminal pins 4 firmly in place and to electrically connect the terminal pins 4 with the respective electrodes 2 and 3, a solder bead 5 is deposited in each of the concave surfaces. Since the head portion 4a of the terminal pin 4 is merely facing the corresponding concave surface, it is necessary to support the terminal pin 4 during the deposition of the solder bead 5. Accordingly, it is difficult to design a machine for manufacturing the capacitor arrangement described above through high speed automation.
Furthermore, when mounting the above described conventional capacitor arrangement onto a circuit board (not shown), or when connecting a lead line (not shown) to it, soldering is generally carried out for such connections. When the soldering is carried out, the heat applied to the terminal pin 4 may undesirably heat the head portion 4a of the terminal pin 4 and melt the solder bead 5. Thus, the terminal pin 4 may undesirably be detached from the ceramic body 1. To prevent such a detachment, the above described capacitor arrangement is further provided with a synthetic resin coating 6 therearound to maintain the solder bead 5 on the concave and to hold the terminal pin 4 in position. However, the employment of the synthetic resin coating 6 not only complicates the manufacturing process, but also produces a floating capacitance and deteriorates temperature characteristics of electrostatic capacitance.